DIY

I'm looking to install some cutoff switch on this 3-pin connector. It almost looks like a PC 4-pin 12v connector, but it actually connects to a Broan CRV motor. Specific model is the L150L.

I originally wanted a ventilator with a timer, but they installed an inline CRV (intake only) with a crazy 150CFM for a tiny 480sqft suite. Massively overkill, and loud. I'd prefer to put this on a timer, or even better would be a smart switch control. But at the very least a manual switch would be great.

For now, and for the last two years, I just have this unplugged, as shown in the image. The passive ventilation on the connected ducting has been more than enough to turn the air around. But sometimes it'd prefer to enable the intake for a time. I just can't have it on all the time because the air turnaround is nutty, not to mention the blast of cold air in the middle of winter.

Any ideas for a switch that fits this connector, or a DIY switch, and/or something to hook to a timer, OR smart switch somehow?